Pd nanoparticles supported on SiO2, Si3N4 and Al2O3 were studied to examine the effect of particle size and support type on the hydrogenation of 1,3-butadiene. Pd nanoparticles were produced using a reverse micelle method resulting in particles with a remarkably small particle size distribution (σ < < 1 nm). The support type and particle size were observed to affect both catalytic activity and product selectivity. All catalysts showed a decrease of their activity with time on stream, paired with an increase in selectivity to butenes (1-butene and cis/trans-2-butene) from a product stream initially dominated by n-butane. In situ XAFS demonstrated a correlation between the formation of palladium hydride and n-butane production in the early stages (~ 1 h) of reaction. The extent of palladium hydride formation, as well as its depletion with time on stream, was dependent on both particle size and support type. Metallic Pd was identified as the species selective towards the production of butenes.

中文翻译：

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粒径和载体类型对1,3-丁二烯加氢的Pd催化剂的影响。

研究了负载在SiO2，Si3N4和Al2O3上的Pd纳米颗粒，以考察粒径和载体类型对1,3-丁二烯氢化的影响。使用逆胶束法生产Pd纳米颗粒，得到的颗粒粒径分布非常小（σ<<1 nm）。观察到载体的类型和粒度影响催化活性和产物选择性。所有催化剂均显示出随着生产时间的延长其活性降低，同时对最初由正丁烷为主的产物物流对丁烯（1-丁烯和顺式/反式-2-丁烯）的选择性增加。原位XAFS证明了在反应的早期阶段（〜1 h）氢化钯的形成与正丁烷生成之间的相关性。氢化钯形成的程度，以及其随着生产时间的消耗，取决于颗粒尺寸和载体类型。金属钯被确定为对丁烯生产具有选择性的物种。